Apparatus for locking and/or unlocking in particular for an access and/or drive authorization and/or for other services in a motor vehicle in the type of a keyless entries/go functionality are well known in the prior art. For example, in the document EP 1 867 535 B1 such an apparatus is disclosed.
In a known apparatus a first device is arranged in the motor vehicle, which is able to activate a second device designed in the type of an electronic key, an ID-transponder, a chip card or the like. Both devices for the intended apparatus have transmitters and/or receivers for electromagnetic signals.
In the known apparatus, the second device remains in a standby status when the second device is not in the operating mode.
When the second device comes into the receiving range of the first device the first device activates the second device for further operating. In the standby mode the second devices is in a status of little power consumption. Nethertheless this little power consumption is a limitation for the battery life time of the second device. For this reason, known apparatus for locking and/or unlocking are working with LF-transmitters to reduce the power consumption.
A disadvantage of such apparatus working with LF-transmitters is the small operating distance between the first and the second device.